As it is known, as the weight of vehicles must be lighter, the pieces made of aluminium and magnesium used in basic elements in the construction of said vehicles must also decrease in weight. In order to do so, the vacuum technology in die casting is essential for achieving pieces with even thinner walls and porosity-free pieces, thus meaning that the entire injector unit must be adapted accordingly, the aim of the present invention being the development of a new piston for cylinders of the injection machines that use said vacuum technology, which has been improved in several aspects with the aforementioned intention.
In that regard, it should be noted that the piston presented herein is based on the known piston through patent EP0525229A1 owned by Allper A G concerning a “Piston, especially for pushing out liquid metal from a casting cylinder”, which, although satisfactorily fulfilling the intended function and objectives, has various aspects that can be improved.
More specifically, the aforementioned piston is formed essentially from a cap or external body which is coupled to a support through a bayonet lock and a screw, one of the essential objectives of the present invention being to improve said locking system between the external body and the piston support, since the wear of the surface material of said body with the cylinder sleeve or container means that frequent replacement is necessary.
Moreover, given the application to which the piston of the invention is intended, the inner support preferably injects cooling fluid inside the external body, a second object of the present invention being to improve the cooling of the external body and, at the same time, extend the life thereof.
In reference to the current state of the art, it should be mentioned that, at least as far as the applicant is concerned, they are not aware of the existence of any other piston or invention with similar application having technical, structural and constituent characteristics similar to those of the invention claimed herein.